A pioneer in climate science, Hansen testified at Al Gore’s seminal Congressional hearings on global warming in the late 1980s. Several years ago, when the federal government tried to muzzle climate scientists and computer models suggested tipping points were near, Hansen came out swinging. He was arrested at a demonstration against coal, and has become increasingly outspoken about the urgency of moving to cleaner fuels to run our economy.

Location: Club Office, 595 Market St.Time: 6:30 p.m. check-in, 7 p.m. programCost: $15 members, $25 non-members, students free (with valid ID). Premium (seatingin the first few rows) $35 members, $45 non-membersBuy the Book: Purchase James Hansen's Storms of My Grandchildren from The Commonwealth Club's online bookstore. If you order the book fewer than 5 business days before the event, and it will be available for pickup at the Commonwealth Club in San Francisco on the day of the event. If you purchase it more than 5 days before the event, the book will be sent to your address.Also know: The speakers and audience will be videotaped for future broadcast on the Climate One program on KRCD public TV 22 on Comcast and DirecTV in the Bay Area.